The major goal of the NOB laboratory investigations is to develop novel experimental therapeutics, the most promising of which will hopefully be brought to the clinic to treat adults and children with incurable malignant brain tumors. The permeability of the blood-brain barrier (BBB) in a growing glioma is poorly understood. Independently, perfusion and enhancement of contrast agents have been the standard for measuring an open or closed BBB. With the use of in vitro studies and animal models, we can evaluate in real time, changes in BBB permeability with intratumoral microdialysis and imaging. Our research aims to identify changes in drug concentrations and tumor dynamics as the invasive glioma progresses.